PREDACEOUS ENEMIES. 



129 



and, as soon as hatched, the larvae seem possessed of an insatiable 

 appetite, devouring aphidids or even eggs and larvae of their own 

 species if no plant-lice are at hand. Mr. Kelly has found that an 



Fig. 38.— The convergent lady-beetle ( Hippodamia convergens) , an enemy of the spring grain-aphia: a, Adult; 

 b, pupa; c, larva. Enlarged. (From Chittenden.) 



adult ladybird {Hippodamia convergens) (fig. 38) will devour from 15 

 to 30 plant-lice in a day. Mr. S. J. Hunter, in ' ' The Green Bug and its 

 Enemies," page 6, states that instances have come under his observa- 

 tion where as many as 100 have been devoured in a single day by an 

 adultlady-beetle. The larvae when nearly 

 grown are probably able even to exceed 

 this record. In one of Mr. Kelly's experi- 

 ments a single beetle deposited as many 

 as 264 eggs, thus showing that this lady- 

 bird is very prolific. When all of these 

 facts are considered it is 

 easy to see that the lady- 

 beetles are rather formida- 

 ble enemies of Toxoptera. 

 Hippodamia convergens 

 appeared to be by far the 

 most abundant ladybird 

 in the Southwest in 1907. 



Coccinella 9-notata (figs. 39, 40) and Megilla maculaia 

 (fig. 41) were also quite abundant. Coccinella dbdomi- 

 nalis was present in less abundance . Adaliaflavoma c- 

 ulata DeG. (fig. 42), with its larvae, has been sent to 

 the bureau as an enemy of Toxoptera in the Orange 

 Free State, South Africa. 



Syrphid Flies. 



All through the Southwest in 1907 syrphids were very abundant 

 and were an important factor in the control of Toxoptera. 



These insects are beautiful two-winged flies with prominent golden 

 bands across the abdomen. They are always present in mild weather 

 26675°— Bull. 110—12 9 



Fig. 39. — The nine-spotted lady-beetle 

 {Coccinella 9-notata), an enemy of 

 the spring grain-aphis: Adult. En- 

 larged. (From Chittenden.) 



Fig. 40.— The nine- 

 spotted lady-bee- 

 tle {Coccinella 9- 

 notata), an enemy 

 of the spring grain- 

 aphis: Larva. En- 

 larged. (From 

 Chittenden.) 



